Is my engine toast?!

I’ve got the engine out to change the push rod tubes and to tidy up a few things. First head I took off and this is lurking below . Do I need new pistons and barrels?!

not opened up the other side yet. Wondering what would have caused this. Smells of fuel in there.

was running fine when removed in October

 

Only looking on my phone so hard to tell, but is that rusty where in there? Is the inlet valve sunk into the head ?

 

You've had the engine out since October?
I'd be tempted to whip the barrels and pistons off too, give everything a good clean and reassemble if you see nothing obvious.

 

First picture in the barrel is a big rusty area at the bottom

 

yep, only just got round to sorting it! What are the obvious things? Never gone as far as removing barrels and pistons before

 

The obvious thing to say is that if you hadn't looked you'd never have known.

 

True. I did wash it down shortly after removing. I guess there’s a chance some water got in between the head and the barrel? The head came off really easily after I undid the bolts. Or maybe it went in past the valves, potentially therefore not something that was there when I removed the engine.

 

Looks like the head/barrels was a good seal. No sooty marks to show combustion leaks.

 

Heads and pistons just look like old well used pistons, try a bit of wd40 and fine Emery on that rust , it’s probably nothing

 

How is the end float?

 

Your carburettor is set up very rich hence all the carbon,, yes you sprayed water down the carburettor into a cylinder with intake valve open.
Rust looks like a recent soaking. Clean it up and dont be so enthusiastic about spraying your air filters.

if it smells of fuel, that would be partly because it didnt burn all the fuel you chucked in there trying to start it last time.
If your oil smells of fuel, thats a different matter, and not related to the water. Check the carburettor fuel metering valve(s) for wear (weber) or sticking open (solex)

 

I’ve cleaned up the area and now, whilst not rusty, the cylinder wall is now quite noticeably rough and pitted. Time for new pistons and barrels?

If I go this route is it worth increasing the CC?

 

Here we go.

 

struggling to see which bits you washed ....

you have two choices ..

bash it back together and run it

complete rebuild = everything from bottom to top

 

Is it stock at the moment or a 1641? ..
People do 1641 because it costs the same, no machining needed, "just drop in" new cylinders and pistons.
While its apart, clean the carbon off the cylinder heads around the valve seats and the spark plug holes, searching for cracks.

Was the end float within specification? - Did the oil pressure light flicker ? All inputs into the decision tree ..
Maybe one outcome being a full rebuild and increase in capacity..
And maybe the other extreme outcome being to put it back together and plan while using the engine until the compression fades away on that cylinder ..

 

it’s standard at the moment, can’t feel any end float and not had the oil light flickering.

I think 1641 new pistons and barrels, cleaning up the heads and bolting back together would be a good plan from here. Will order the kit from heritage

 

This is a close up of the damage, looks bad!

 

Yes.

 

Just think.. if you had used the engine regularly rather than washing it and putting it away unused, it probably would have spat out that small amount of water, started, warmed up and dried out.

 

yup, stuffed myself there

will be googling a guide for fitting new barrels and pistons - hopefully not a nightmare job!